The United Nations was drawing up plans for a 200-strong monitoring mission to Syria after its envoy, Kofi Annan, declared that the Assad regime had failed to implement his peace plan by withdrawing troops from the streets.
Residents of Syria's major cities reported a downturn in violence as a ceasefire came into effect on Thursday morning, though there were sporadic outbreaks which both sides blamed on each other.
But Mr Annan backed the major activist groups who claimed the regime had failed to honour its promise to withdraw troops and tanks from towns and cities. He told the UN security council by video from Geneva that he wanted it to authorise its own monitoring mission to supervise the ceasefire.
He also challenged the council, including the regime's key allies Russia and China, to issue a formal demand that it comply with the demand to withdraw troops.
Russia said it would back the monitoring mission, which has also been agreed by Syria and is likely to be approved by a security council resolution on Friday. The first team of observers might leave by the weekend, according to reports.
But key may be whether the resolution contains any reference to President Bashar al-Assad having broken the peace plan's terms – a rebuke of the sort that the two powers have vetoed twice already.
In Geneva, both Mr Annan and Ban Ki-moon, the UN secretary-general, said the ceasefire was encouraging but "fragile".
"As of this moment the situation looks calmer," Mr Ban said. "The world is watching, however, with sceptical eyes, since many promises previously made by the government of Syria had not been kept. The onus is on the government of Syria to prove that their words will be matched by their deeds at this time."
Rami Jarrah, a Cairo-based activist whose group is in regular contact with cities across the country, said: "There have been a number of shellings and gunfire reports, but generally it has been relatively quiet. There were incidents in Idlib province, Zabadani, and Aleppo, he said.
An outbreak of shooting in Aleppo was followed by a government statement which said there had been a "terrorist" bomb attack on an army vehicle which killed an officer and injured 24 other soldiers.
An activist in Zabadani who called himself "Zean" said overnight shelling had continued after the deadline. "I think he did this to threaten us. 'If you do anything against, we will shoot' – I think this is the message from the shelling this morning," he said by Skype.
Waleed Fares, an activist in Khalidiya, one of the worst-hit suburbs of Homs, said the city had been peaceful but that the army had not been withdrawn. "I can move around inside Khalidiya, but I cannot leave the neighbourhood," he said. "There are tanks in the street and snipers on the rooftops."
The real test will come today, the main day of protest during the Arab Spring. Some demonstrations were allowed to take place in Damascus yesterday without the live fire that has regularly followed in the last year, though both Mr Jarrah and "Maher", a resident of the city, told The Daily Telegraph that others had been broken up.
"We protested for about 20 minutes," Maher said. "This is not so common – usually we can only meet for two or three minutes before the security forces start shooting at us." He said a second protest had been ended by security forces shooting into the air, while Mr Jarrah said protesters had been arrested.
"Tomorrow is Friday – only then we will know if this is a real ceasefire," Maher added.
A UN monitoring mission would put far more pressure on the regime than the only previous such effort, organised by a badly split Arab League in December.
Hillary Clinton, US secretary of state, said G8 foreign ministers, meeting in Washington, had welcomed Mr Annan's report, but that it must lead to a "political transition".
William Hague, the foreign secretary, and in a joint, public video conference Presidents Barack Obama and Nicolas Sarkozy, all stated that the Syrian regime had failed to fully honour its commitments.
“I urge the Assad regime to implement fully its undertakings to the Joint Arab League and UN Special Envoy on Syria, including withdrawing troops and weaponry from residential areas,” said Mr Hague. “The Syrian government has a record of failing to keep its promises. It has the opportunity to change that now: it should seize it.”